Histocompatibility profile in Chinese with ankylosing spondylitis

Using the two-step microcytotoxicity test as recommended by NIH, U.S.A., 66 Chinese of definite ankylosing spondylitis (AS), 41 their first-degree relatives, and 43 normal Chinese received HLA analysis. The positive rates of HLA-B27 of these 3 groups were 95.5%, 56.1%, and 4.7% respectively. The results indicate: (i) The positive rate of HLA-B27 in patients with AS is significantly higher than their first-degree relatives, or the normal controls. (ii) The high positive rate of HLA-B27 in Chinese with AS is similar to those of other races.